Several studies in recent years have highlighted the potential of Newcastle disease virus (NDV) to be used as a vaccine vector for avian diseases (Krishnamurthy et al., Virology 278, 168-182,2000; Huang et al., J. Gen. Virol. 82, 1729-1736, 2001; Nakaya et al., J. Virol. 75, 11868-11873, 2001; Park et al. PNAS 103, 8203-8208, 2006; Veits et al PNAS 103, 8197-8202, 2006; Ge et al. J. Virol. 81, 150-158, 2007; Romer-Oberdorfer et al. Vaccine 26, 2307-2313, 2008).
NDV belongs to the Paramyxovirinae family and the Avulavirus genus. NDV replicates in respiratory and gastrointestinal tracts, in the oviduct, and for some isolates, in the nerve system. The transmission is aerogenic and by oral and fecal routes. NDV causes a highly contagious and fatal disease affecting all species of birds, and can infect some mammalian species. The disease can vary from clinically unapparent to highly virulent forms, depending on the virus strain and the host species. The continuous spectrum of virulence displayed by NDV strains enabled the grouping of them into three different pathotypes: lentogenic, mesogenic, and velogenic (Alexander, D. J., Diseases of Poultry, Iowa State Uni. Press, Ames Iowa, 541-569, 1997). Lentogenic strains do not usually cause disease in adult chickens and are widely used as live vaccines in poultry industries in the United States and other countries. Viruses of intermediate virulence are termed mesogenic, while viruses that cause high mortality are termed velogenic. The disease has a worldwide distribution and remains a constant major threat to commercial poultry production.
The NDV genome is a non-segmented negative strand of RNA of approximately 15 kb. The genomic RNA contains six genes that encode the following proteins in the order of: the nucleocapsid protein (NP), phosphoprotein (P), matrix protein (M), fusion protein (F), haemagglutinin-neuramimidase (HN) and large polymerase protein (L). Two additional proteins, V and W, of unknown function are produced by RNA editing during P gene transcription (Steward et al., 1993, Journal of General Virology 74:2539-2547).
The development of methods to recover non-segmented negative RNA viruses entirely from cloned cDNA, established in recent years, opened up the possibility of genetically manipulating this virus group, including NDV (Conzelmann, K. K., Ann. Rev. Genet. 32, 123-162, 1998; Roberts and Rose, Virology 247, 1-6, 1998). This unique molecular genetic methodology, termed “reverse genetics”, provides a means not only to investigate the functions of various virus-encoded genes (Palese et al., PNAS 93, 11354-11358, 1996; Nagai, Y., Rev. Med. Virol. 9, 83-99, 1999) but also to allow the use of these viruses to express heterologous genes (Bukreyev et al., J. Virol. 70, 6634-6641, 1996; Mebatsion et al., PNAS 93, 7310-7314, 1996; Schnell et al., PNAS 93, 11359-11365, 1996; Hasan et al., J. Gen. Virol. 78, 2813-2820, 1997; He et al., Virology 237, 249-260, 1997; Sakai et al., FEBS Lett. 45, 221-226, 1999). This provides a new method of generating improved vaccines and vaccine vectors. Recently, NDV was used as a vector for expression of avian influenza antigens (US2010/0255029, Merial Limited).
The Herpesvirus glycoprotein D (gD) is essential for FHV-1 (Feline Herpesvirus-1) entry and is involved in interaction with host cell (binding to receptors). The gD protein has haemagglutination activities on feline red blood cells (Maeda et al., Virology 202, 1034-8, 1994; Maeda et al., Virus Res. 46, 75-80, 1996). The Herpesvirus glycoprotein B (gB) is essential for FHV entry and is involved in fusion process (Spatz and Maes, Virology 197, 125-36, 1993; Maeda et al., Virus Res 39, 55-61, 1995). Both glycoproteins can induce neutralizing antibodies (Horimoto et al., Arch Virol 111, 127-32, 1990).
Considering the susceptibility of animals, including humans, to herpesvirus, a means of preventing herpesvirus infection and protecting animals is essential. Accordingly, there is a need for an effective vaccine against herpesvirus.
Citation or identification of any document in this application is not an admission that such document is available as prior art to the present invention.